Quantum Computers
What is a Quantum computer?
Quantum computers are machines that use the properties of quantum physics to store data and perform computations. Classical computers, which include smartphones and laptops, encode information in binary “bits” that can either be 0's or 1's. In a quantum computer, the basic unit of memory is a quantum bit or qubit.
Qubits are made using physical systems, such as the spin of an electron or the orientation of a photon. These systems can be in many different arrangements all at once, a property known as quantum superposition. Qubits can also be inextricably linked together using a phenomenon called quantum entanglement. The result is that a series of qubits can represent different things simultaneously.
Quantum computers need to protect qubits from external interference, either by physically isolating them, keeping them cool or zapping them with carefully controlled pulses of energy. Currently, Quantum computers are highly sensitive: heat, electromagnetic fields and collisions with air molecules can cause a qubit to lose its quantum properties. This process, known as quantum decoherence, causes the system to crash, and it happens more quickly the more particles that are involved.
Quantum computers get their edge over classical ones. In situations where there are a large number of possible combinations, quantum computers can consider them simultaneously. Examples include trying to find the prime factors of a very large number or the best route between two places. Another advantage of Quantum computers over classical ones, is in bit calculations. In a classical computer eight bits is enough bits to represent any number between 0 and 255. But eight qubits is enough for a quantum computer to represent every number between 0 and 255 at the same time. A few hundred entangled qubits would be enough to represent more numbers than there are atoms in the universe.
However, with all these advances, there may be plenty of situations where classical computers will still outperform quantum ones. So computers of the future may be a combination of both of these types.
Quantum bit or "Qubit"
In quantum computing a quantum bit or "qubit" is the basic unit of quantum information which is equivalent to the classic binary bits in computer systems today. In classical computing binary bits are the 0's and 1's which can only be in one state or the other. In Quantum computing a qubit can be in both states simultaneously. This phenomenon or behavior is known as quantum superposition.
IBM's Quantum Computer
Scientists and engineers have been working to build a fully fledged quantum computer able to perform useful calculations that would out perform any conventional supercomputer. Today these new machines contain just a few dozen quantum bits, or qubits, but so far not enough to do anything useful. But, recently, IBM announced a road map for the development of its quantum computers, including the lofty goal to build a quantum computer which will contain 1000 qubits by the middle of the decade. Today, IBM’s current quantum computer, pictured here on the left, contains around 65 qubits.
IBM is not the only company working on a quantum computer, Google, recently grabbed headlines when the company announced its researchers had used their 53-qubit quantum computer to solve a particular abstract problem that they claimed would out perform any current conventional computers. Google also announced its plans to build a million qubit quantum computer to further its endeavor in the quantum computing space.